JPH05194685A - Ethylene-propylene block copolymer - Google Patents

Abstract

PURPOSE:To obtain an ethylene-propylene block copolymer having excellent rigidity, impact strength and melt flowability and excellent appearance of molded article. CONSTITUTION:An ethylene-propylene block copolymer having a weight ratio of crystalline polypropylene part and ethylene-propylene random copolymer part of 95-80/5-20, 0.8-2.0dl/g intrinsic viscosity [eta]P of crystalline polypropylene part, a specific Q value (weight-average molecular weight Mw/number-average molecular weight Mn) of molecular weight measured by GPC of 3.0-5.0, <=1.5wt.% xylene soluble part at 20 deg.C, 20-60wt.% ethylene content of propylene- ethylene random copolymer part and 3.5-8.5dl/g intrinsic viscosity [eta]EP.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an ethylene-propylene block copolymer having excellent rigidity, impact resistance, tensile properties, heat resistance and the like.

[0002]

2. Description of the Related Art Polypropylene has excellent characteristics and
Since it is relatively inexpensive, it is widely used for daily necessities, home appliances parts, automobile parts, industrial parts, etc., but with the increase in size and weight of molded products, the wall thickness is becoming thinner. Therefore, highly fluid polypropylene or polypropylene resin composition having excellent heat resistance, rigidity and impact resistance has been demanded. For the purpose of improving these drawbacks, many polypropylene compositions have been proposed in which crystalline polypropylene is mixed with polyethylene or a rubber-like substance such as an amorphous ethylene-propylene copolymer. Further, in order to improve the decrease in rigidity and heat resistance due to the addition of a rubber-like substance,
Many compositions have been proposed in which an inorganic filler such as talc is added. However, the addition of the rubber-like substance or the inorganic filler significantly lowers the melt fluidity, causes a striped pattern or so-called flow mark peculiar to the injection-molded article, and deteriorates the strength and appearance of the weld portion. As a method of improving melt fluidity, a method of adding a small amount of an organic peroxide to polypropylene having a low melt fluidity or a composition thereof and performing heat treatment is known. However, the polypropylene obtained by such a method has a decrease in rigidity and a problem of odor due to heat treatment.In addition, a composition containing a rubber-like substance or an inorganic filler causes a strong flow mark on the surface of the injection-molded article. There are problems such as poor appearance. Therefore, development of polypropylene excellent in rigidity, impact resistance, melt fluidity, etc. without requiring such heat treatment is strongly desired. So-called block copolymers are known as polypropylene with good rigidity and impact resistance, but household appliances parts that require high impact resistance, especially impact resistance at low temperatures, rigidity, and heat resistance, It is still insufficient as a vehicle outer panel material or interior material in terms of balance of fluidity, rigidity and impact strength.

[0003]

In view of the situation of the prior art, the present invention is excellent in rigidity, impact strength and melt fluidity,
Moreover, it is an object of the present invention to provide an ethylene-propylene block copolymer having a good appearance of a molded product.

[0004]

SUMMARY OF THE INVENTION The present invention provides a propylene homopolymer or a polypropylene part in which propylene is copolymerized with ethylene or an α-olefin having 4 or more carbon atoms in an amount of 1 mol% or less and the composition of ethylene and propylene is in a weight ratio. And ethylene / propylene = 20/80 to 60/40 having an ethylene-propylene random copolymer portion,
(1) Intrinsic viscosity [η] _{P of} polypropylene is 0.8
˜2.0 dl / g, the ratio Q value of the molecular weight measured by GPC (weight average molecular weight M _w / number average molecular weight _MN ) is 3.0 to
5.0, 20 ℃ xylene solubles 1.5% by weight or less,
(2) The ethylene-propylene block copolymer has an intrinsic viscosity [η] _EP of 3.5 to 8.5 in the ethylene-propylene random copolymer portion and (3) 5 to 20% by weight of the total polymer. It is united.

The ethylene-propylene block copolymer in the present invention is a propylene homopolymer or a copolymer of propylene and ethylene or an α-olefin having 4 or more carbon atoms (eg, butene-1, hexene-1) at 1 mol% or less. The polypropylene part and the composition of ethylene and propylene are ethylene / propylene = 20/80 by weight ratio.
It has an ethylene-propylene random copolymer portion of about 60/40 and contains an ethylene-propylene random copolymer portion of 5 to 20% by weight based on the whole polymer.

The block copolymer is usually obtained by two-step polymerization in the presence of a Ziegler-Natta catalyst in combination with titanium trichloride and an alkylaluminum compound. In carrying out the present invention, titanium trichloride is used. It is preferable to use a catalyst composed of a complex of magnesium and magnesium, a trialkylaluminum compound and an electron-donating organic compound.

A method for producing this catalyst is described in, for example, JP-A-61-161.
It is described in detail in Japanese Patent No. 218606. That is,
(A) In the presence of a silicon compound having a Si—O bond,
General formula Ti (OR ¹)_nX_4-n(R¹Has 1 to 20 carbon atoms
Hydrocarbon group, X is a halogen atom, n is a positive number of 0 <n ≦ 4
Number), the titanium compound represented by
The solid product obtained by reduction with the compound is an ester compound
And a mixture of ether compound and titanium tetrachloride
Obtained trivalent titanium compound-containing solid catalyst component,
(B) Organoaluminum compound, (C) Si-OR²Conclusion
Go (R²A hydrocarbon group having 1 to 20 carbon atoms)
Homopolymerization of propylene using a catalyst composed of iodine compounds
Alternatively, it can be obtained by copolymerization.

The silicon compound having a Si--O bond is
It is represented by the following general formula. Si (OR ³ )
_m R ⁴ _4-m , R ⁵ (R ⁶ SiO) _P SiR ⁷ ₃ or (R
⁸ ₂ SiO) _q where R ³ is a hydrocarbon group having 1 to 20 carbon atoms, and R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ have 1 to 2 carbon atoms.
0 hydrocarbon group or hydrogen atom, m is a number 0 <m ≦ 4,
p is an integer of 1 to 1000 and q is an integer of 2 to 1000. Specific examples of the organosilicon compound include tetramethoxysilane, dimethyldimethoxysilane, diethoxydiethylsilane, diethoxydiphenylsilane, triethoxyphenylsilane, cyclohexylethyldimethoxysilane, and phenyltrimethoxysilane.

As the organomagnesium compound, any type of organomagnesium compound containing a magnesium-carbon bond can be used. Particularly, a Grignard compound represented by the general formula R ⁹ MgX (R is a hydrocarbon group having 1 to 20 carbon atoms, and X is a halogen) and the general formula R ¹⁰ R ¹¹ Mg (R ¹⁰ ,
R ¹¹ is preferably a dialkyl magnesium or diaryl magnesium compound represented by a hydrocarbon group having 1 to 20 carbon atoms. Here, R ¹⁰ and R ¹¹ may be the same or different.

Examples of the ester compound include monocarboxylic acid and polycarboxylic acid esters such as aliphatic carboxylic acid ester, olefinic carboxylic acid ester, alicyclic carboxylic acid ester and aromatic carboxylic acid ester. Among these ester compounds, olefinic carboxylic acid esters such as methacrylic acid esters and maleic acid esters and phthalic acid esters are preferable, and diesters of phthalic acid are particularly preferable.

The ether compound is preferably a dialkyl ether such as diethyl ether, di-n-propyl ether, diisopropyl ether, dibutyl ether, diamyl ether or methyl-n-butyl ether, and particularly di-n-butyl ether or di-n-butyl ether. Isoamyl ether is preferred.

In the polymerization, the ratio of the organoaluminum compound and the titanium compound / magnesium compound composite is 3/1.
It can be selected within the range of up to 20/1. Also Si-OR
The ratio of the silane compound having ^two bonds and the titanium compound / magnesium compound composite can be selected within the range of 1/10 to 1/2 (mol / mol).

The ethylene-propylene block copolymer of the present invention comprises the following components (I) and (II). (I) The crystalline polypropylene part has (1) an intrinsic viscosity [η] _{p in} 135 ° C tetralin of 0.8 to 2.0 dl.
/ G, preferably 0.8 to 1.7 dl / g, more preferably 0.85 to 1.5 dl / g, (2) G
Q value (weight average molecular weight M _w / number average molecular weight _MN ) measured by PC is 2.5 to 5.5, preferably 3 to 5,
And (3) occupy 95 to 80% by weight of the total copolymer amount, and (II) the ethylene-propylene random copolymer portion,
(1) Intrinsic viscosity [η] _{EP in} tetralin at 135 ° C. is 3.5 to 8.0 dl / g, preferably 3.5 to 7.0 d.
1 / g, (2) ethylene and propylene composition is 2 by weight ratio
0/80 to 60/40 (weight ratio), and (3)
It accounts for 95 to 80% by weight of the total amount of the copolymer.

This ethylene-propylene block copolymer is produced by a slurry polymerization method or a gas phase polymerization method in which the above (I) and (II) are successively carried out in two steps, and the slurry polymerization method is preferred. If [η] _p of (I) is less than 0.8 dl / g, the mechanical strength will be reduced, and if it is 2.0 dl / g or more, the melt fluidity of the ethylene-propylene block copolymer and its composition will be low. descend. Q value is 5.5
If it is above, the weld line of the injection-molded product obtained from the ethylene-propylene block copolymer and its composition will appear strongly, and if it is 3 or less, a flow mark will occur.
If the intrinsic viscosity [η] _{EP of} (II) is 3.5 dl / g or less, the impact resistance is low, and if it is 8.0 dl / g or more, the melt fluidity is deteriorated and the composition components are poorly dispersed. The impact resistance is deteriorated. Further, when the ethylene content in the ethylene-propylene random copolymer is 20% by weight or less, or 60% by weight or more, the impact resistance of the molded product is deteriorated, which is not preferable.

The resin of the present invention may be used alone or in ethylene / α
-Used as a composition containing olefin rubber and an inorganic filler. When compounding an inorganic filler or the like, the crystalline ethylene-propylene block copolymer of the present invention is 50% by weight or more, the inorganic filler is 5 to 40% by weight and / or the ethylene-α-olefin random copolymer rubber 5 ~
It contains 40% by weight. That is, the composition can have the following compositions (1), (2) and (3). (1) Crystalline ethylene-propylene block copolymer: 50 to 95% by weight Inorganic filler: 5 to 40% by weight (2 ) Crystalline ethylene-propylene block copolymer: 50 to 95% by weight Ethylene-α-olefin random copolymer rubber: 5 to 40% by weight (3) Crystalline ethylene-propylene block copolymer: 50 to 95% by weight inorganic filler ... 5 to 40% by weight Ethylene-α-olefin random copolymer rubber ... 5 to 40 However, the total of each component is 100% by weight.

As the inorganic filler, talc, mica, calcium carbonate, wollastonite, glass fiber or the like is used. Among these inorganic fillers, talc having an average particle diameter of 4.0 μm or less, preferably 3.5 μm to 1.0 μm, is taken into consideration in consideration of the effect of improving rigidity, appearance and the like.
If it is 4.0 μm or more, the impact strength of the molded product is lowered, and if it is 1.0 μm or less, it is unpractical, which is not preferable. The amount of talc used is 5 to 40% by weight, preferably 10 to 35% by weight. If this amount is 5% by weight or less, the effect of improving the rigidity is small, and if it is 40% by weight or more, the impact resistance decreases, which is not preferable.

The ethylene-α-olefin random copolymer rubber has an ethylene content of 85% by weight to 40% by weight,
It is preferably 85% by weight to 65% by weight, and those having a Mooney viscosity ML _{1 + 4} measured at 121 ° C. of 15 to 80, preferably 20 to 70, and an iodine value of 0 to 15 are suitably used. When the ethylene content is 40% by weight or more, the rigidity of the molded product is largely reduced, and the ethylene content is 85% by weight.
If it is above, the effect of improving the impact resistance is small. When the Mooney viscosity exceeds 70, the fluidity of the composition is lowered, or the impact strength is lowered due to poor dispersion of rubber particles.
Further, when the Mooney viscosity is 10 or less, the dispersed particle diameter of rubber in the composition is too small, the effect of improving impact resistance is small, and the surface of the injection-molded product is uneven, which is not preferable.

Specific examples of the α-olefin copolymerizable with ethylene include propylene, 1-butene, 4-methyl-pentene-1,1-hexene, and the like.
Propylene or 1-butene are preferred. The ethylene-α-olefin random copolymer rubber is copolymerized with a small amount of a non-conjugated diene monomer such as ethylidene norbornene, dicyclopentadiene and 1,4-hexadiene as an iodine value of 0 to 15, preferably about 0 to 10. It may have been done. These ethylene-α-olefin copolymer rubbers can be used as a mixture of two kinds or several kinds according to respective purposes such as fluidity of the composition, impact strength and hardness of a molded product. The amount used is 5 to 40% by weight, preferably 5
Incorporate an amount of ˜35% by weight. If the ethylene-α-olefin random copolymer is 5% by weight or less, the effect of improving impact resistance is small, and if it exceeds 40% by weight, the rigidity is largely decreased, which is not preferable.

This ethylene-α-olefin random copolymer rubber is usually polymerized in a hydrocarbon solvent in the presence of a catalyst composed of a vanadium compound and an organoaluminum compound. As the vanadium compound, vanadium oxytrichloride, vanadium tetrachloride, vanadate compound, and as the organoaluminum compound, ethylaluminum sesquichloride, diethylaluminum chloride or the like is used, and by polymerizing in a solvent such as hexane or heptane. Manufactured.

The composition of the present invention is prepared by mixing the ethylene-propylene block copolymer, the ethylene-α-olefin random copolymer rubber and / or the inorganic filler with a tumbler, a Henschel mixer, a ribbon blender, etc.
It can be produced by melt-kneading with a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneader or the like. By using an extruder having excellent kneading performance such as a twin-screw extruder, a Banbury mixer, or a kneader, it is possible to obtain a high-quality composition in which each constituent component is uniformly dispersed. The respective components may be kneaded at the same time or may be divided. As a method of dividing and kneading, after kneading the ethylene-propylene block copolymer and talc, a method of adding an ethylene-α-olefin random copolymer rubber or a part of the ethylene-propylene block copolymer And ethylene-α-olefin random copolymer rubber are mixed in advance to form a masterbatch, and the mixture is separately kneaded with a crystalline ethylene-propylene block copolymer and an inorganic filler, ethylene-propylene block copolymer , A crystalline polypropylene and talc are kneaded at a high concentration to form a masterbatch, which is separately produced by a method such as kneading with an ethylene-propylene block copolymer, a crystalline polypropylene and an ethylene-α-olefin random copolymer rubber. To be done.

In addition to the basic components of these compositions,
Add additives such as antioxidants, UV absorbers, lubricants, antistatic agents, copper damage inhibitors, flame retardants, neutralizers, nucleating agents, foaming agents, plasticizers, pigments, dyes, etc. according to their purpose. You can do it. Among these additives, it is desirable to add an antioxidant or an ultraviolet absorber in order to improve heat resistance, weather resistance and oxidation stability.

The ethylene-propylene block copolymer of the present invention and the composition thereof are excellent in rigidity, impact resistance and melt flowability, and the appearance of the molded article is good. It is molded by the method and is suitably used for automobile outer panels, automobile interior applications, large-scale home electric appliances such as washing tubs.

The ethylene-propylene block copolymer of the present invention is produced by such a method.
When used in applications requiring rigidity, scratch resistance, luster, etc., the boiling polypropylene heptane of the crystalline polypropylene polymerized in the first step has an isotactic pentad fraction of 0.970 or more, and the boiling heptane. It is preferable to use a highly crystalline polypropylene having a soluble portion content of 5.0% by weight or less and a 20 ° C. xylene soluble portion content of 1.5% by weight or less. The isotactic pentad fraction of the boiling heptane-insoluble portion, the content of the boiling heptane-soluble portion, and the content of the polymer soluble in xylene at 20 ° C. are determined as follows. After completely dissolving 5 g of crystalline polypropylene in 500 ml of boiling xylene, the temperature is lowered to 20 ° C. and the mixture is left standing for 4 hours. Then, this is separated by filtration to separate the xylene-insoluble portion at 20 ° C. The filtrate is concentrated and dried to evaporate xylene, and then dried under reduced pressure at 60 ° C. to obtain a polymer soluble in xylene at 20 ° C. The value obtained by dividing the dry weight by the weight of the charged sample and expressed as a percentage is the content of the 20 ° C. xylene-soluble portion. 20
After the xylene-insoluble part is dried, it is Soxhlet extracted with boiling n-heptane for 8 hours. This extraction residue is called a boiling heptane-insoluble part, and the value obtained by subtracting the value obtained by subtracting the dry weight from the charged sample weight (5 g) by the charged sample weight is expressed as a percentage, which is the content of the boiling heptane-soluble part. is there.

The isotactic pentad fraction is
A. Zambilli et al., Macromolec
ules, 6 , 925 (1973), that is, the isotactic chain at the pentad unit in the crystalline polypropylene molecular chain measured using ¹³ C-NMR, in other words the propylene monomer unit 5
It is the fraction of propylene monomer units at the center of a chain in which individual meso-bonds are continuous. However, regarding the attribution of the NMR absorption peak, Macromole published later
Cules, 8 , 687 (1975). Specifically, the isotactic pentad fraction is measured as the area fraction of the mmmm peak in all the absorption peaks in the methyl carbon region of the ¹³ C-NMR spectrum.
By this method, British National PHYSICA
L LABORATORY NPL Reference Material CRM N
o. M19-14 PolypropylenePP /
The MWD / 2 isotactic pentad fraction was measured and found to be 0.940.

[0025]

The present invention will be described below with reference to examples, but these are merely examples, and the present invention is not limited to these examples without departing from the gist thereof.

Next, methods for measuring physical property values in Examples will be described below. (1) GPC measurement conditions It was measured by gel permeation chromatography (GPC) under the following conditions. The calibration curve was prepared using standard polystyrene. Model: Millipore Waters 150CV column: Shodex M / S 80 Measurement temperature: 145 ° C, solvent orthodichlorobenzene Sample concentration: 5 mg / 8 ml Under these conditions, NBS (National Bureau of Standard)
s) Standard Reference Material 706 (Mw / M
When polystyrene (n = 2.1) was measured, a molecular weight distribution (Q value) Mw / Mn = 2.1 was obtained.

(2) Melt flow rate (MFR) According to the method specified in JIS K 6758. The measurement temperature is 230 ° C. and the load is 2.16 kg. (3) Tensile test According to the method specified in ASTM D638. A test piece molded by injection molding is used. The thickness of the test piece is 3.2 mm, and the tensile yield strength is evaluated. The measurement temperature is 23 ° C. (4) Bending test According to the method specified in JIS K7203. A test piece molded by injection molding is used. The thickness of the test piece is 6.4 mm, and the bending elastic modulus and bending strength are evaluated under the conditions of a span length of 100 mm and a load speed of 2.0 mm / min. The measurement temperature is 23 ° C. (5) Izod impact strength According to the method specified in JIS K 7110. A test piece molded by injection molding is used. The thickness of the test piece is 6.
It is 4 mm and the impact strength with notch that is notched after molding is evaluated. Measurement temperature is -20 ℃ and -30 ℃
Is. (6) Appearance The appearance of the following three types of molded products was visually evaluated. Good ・ ・ ・ ○ 、 Normal ・ ・ ・ △ 、 Poor ・ ・ ・ × Flow mark: A striped pattern that is likely due to the difference in gloss that is easily formed in the part away from the gate of the molding machine. Weld line: A linear pattern that tends to occur at the confluence of the resin during molding. Smoothness: unevenness seen on the plane other than the above weld line. (7) Gloss According to the method specified in JIS Z 8741. The measurement temperature is 23 ° C., the thickness is 3 mm, and the incident angle and the reflection angle are each 60 °.

(8) Production of Composition The composition was produced under the following conditions. Weigh a predetermined amount of each component, and after uniformly premixing with a Henschel mixer,
Continuous twin-screw kneader (TEX 44 SS 30BW-2 manufactured by Japan Steel Works, Ltd.)
V type) with an extrusion rate of 30 kg / hour, a resin temperature of 220 ° C., a screw rotation speed of 350 rotations / minute, and a vent suction. The screw was constructed by arranging a three-row type rotor and a kneading disk in two kneading zones, each in the zone next to the first feed port and the second feed port. It was seen.

(9) Flat plate injection molding conditions Injection molding machine Sumitomo Heavy Industries Neomat 515/150 Cylinder temperature NH H1 H2 H3 H4 220 220 220 220 210 200 (° C) Injection pressure Primary pressure 65 kg / cm ² G Mold temperature 50 ° C Injection time / cooling time 15/30 (seconds) Molded product shape (mm) 100 (width) x 400 (length) x 3 (thickness)

Example 1 SUS with an inner volume of 5.5 m ^{3 and} a stirrer and a jacket
After sufficiently replacing the production reactor with propylene, n-heptane (2.5 m ³⁾ , triethylaluminum (10 mol) and cyclohexylethyldimethoxysilane (1.5 mol) were supplied, and the internal temperature was 20 to 40 ° C. and the pressure was propylene. It is adjusted to 0.2 kg / cm ² G, and 0.12 kg of a solid catalyst component (synthesized by the method shown in Example-1 of JP-A-1-319508) is supplied. Then, hot water was passed through the jacket to raise the internal temperature of the reactor to 75 ° C., and then the reaction pressure was raised to 8 kg / cm ² G with propylene and hydrogen to start the polymerization. Reaction temperature of 75 ° C and reaction pressure of 8 kg / c
Propylene was continuously supplied so as to maintain m ² G, and the polymerization of the crystalline polypropylene part (hereinafter abbreviated as P part) was continued while supplying so that the hydrogen concentration in the gas phase part was maintained at 4.6%. .. When the cumulative amount of propylene supplied reached 1180 kg, the supply of propylene and hydrogen was stopped, the unreacted monomer in the reactor was degassed, and the pressure in the reactor was adjusted to 0.
The pressure was lowered to 5 kg / cm ² G and the temperature inside the reactor was adjusted to 60 ° C. As a result of sampling about 100 g of the polymer in the P part and analyzing it, the intrinsic viscosity [η] _P is 1.02 d.
1 / g, the ratio of molecular weight _Mw / M determined by GPC
_{The n} was 3.5 and the xylene-soluble content at 20 ° C. was 1.2% by weight. The amount of polymer produced in the P part was 846 kg calculated from the cumulative amount of propylene supplied and the weight of unreacted propylene at the time of completion of the polymerization.

Subsequently, the reaction pressure was raised to 3 kg / cm ² G with propylene and ethylene to start the polymerization of the ethylene-propylene copolymerization part (hereinafter abbreviated as EP part), and the reaction pressure was 3 kg at a reaction temperature of 60 ° C. / Cm ² G, a mixed gas of propylene / ethylene = 3/1 (weight ratio) was continuously supplied, and the hydrogen concentration in the gas phase part was 0.01.
Polymerization of the EP part was continued while adjusting so as to keep the content of the EP part. The total amount of propylene / ethylene mixed gas supplied is 18
When the amount reached 8 kg, the supply of the monomer was stopped, the whole amount of the polymer slurry in the reactor was introduced into the deactivation tank, and the deactivation treatment was performed with butyl alcohol. Then, the polymer slurry was centrifuged to obtain a solid polymer. It was recovered and dried with a dryer to obtain 940 kg of powdery white powder.
The intrinsic viscosity [η] _T of the entire polymer obtained was 1.54.
It was dl / g and the ethylene content was 2.3% by weight. The polymerization ratio of the P part and the EP part is calculated from the weight of the polymer finally obtained and the amount of the polymer of the P part, and the weight ratio is 8
It was 9/11. Therefore, the ethylene content of the polymer in the EP part was 24% by weight, and the intrinsic viscosity [η] _EP of the EP part was 6.2 dl / g.

100 parts by weight of the obtained ethylene-propylene block copolymer was added as a stabilizer with 0.05 part by weight of calcium stearate and 2,6-di-t-butyl-4-.
0.2 parts by weight of hydroxytoluene (BHT, manufactured by Sumitomo Chemical), tetrakis [methylene-3 (3 ', 5'-t-butyl-4-hydroxyphenyl) propionate] methane (Irganox 1010, manufactured by Ciba Geigy) 0.
1 part by weight is added, and as a nucleating agent, 0.15 parts by weight of para-tert-butyl aluminum benzoate is added,
After pelletizing using a continuous biaxial kneader, a test piece was prepared by injection molding and the physical properties were measured. The evaluation results are shown in Table 1. The rigidity, mechanical properties such as impact strength at low temperature, elongation at break, fluidity, and appearance of the molded product were good.

Comparative Example 1 SUS with an internal volume of 5.5 m ^{3 and} a stirrer and a jacket
After sufficiently replacing the reactor made with propylene, 2.7 m ^{3 of} n-heptane, 10 mol of diethylaluminum chloride and 1.0 mol of ε-caprolactone were fed, and the internal temperature was adjusted to 20 to 40 ° C., and propylene was added. Set the pressure to 0.
The solid catalyst component was adjusted to ² kg / cm ² G (Japanese Patent Laid-Open No. Sho 60).
It was synthesized by the method shown in Example-1 of No. 228504).
Supply 0.58 kg. Then, hot water was passed through the jacket to raise the internal temperature of the reactor to 50 ° C., and then the reaction pressure was raised to 9 kg / cm ² G with propylene and hydrogen to start polymerization. Reaction temperature 50 ° C, reaction pressure 9 kg / cm ²
Propylene was continuously supplied so as to maintain G, and the polymerization of P part was continued while supplying so as to keep the hydrogen concentration in the gas phase part at 30%. Total amount of propylene supply is 1120 kg
At that point, the supply of propylene and hydrogen was stopped, the unreacted monomer in the reactor was degassed, and the pressure in the reactor was reduced to 0.5 kg / cm ² G. Further, as a result of sampling about 100 g of the polymer in the P part and analyzing it, the intrinsic viscosity [η] _p was 1.38 dl / g, and the molecular weight ratio M _w / M _n determined by GPC was 6.1 and 20 ° C. xylene. The soluble content was 2.5% by weight. The amount of polymer produced in the P part was 735 kg calculated from the integrated amount of propylene supplied and the weight of unreacted propylene at the end of the polymerization.

Subsequently, the reaction pressure was raised to 3 kg / cm ² G with propylene and ethylene to start the polymerization of the EP part. At a reaction temperature of 50 ° C., a reaction pressure of 3 kg / cm ²
A mixed gas of propylene / ethylene = 2.5 / 1 (weight ratio) is continuously supplied so as to maintain G, and the EP part is adjusted while adjusting so that the hydrogen concentration in the gas phase part is maintained at 0.2%. Polymerization was continued. When the cumulative amount of the propylene / ethylene mixed gas supplied reached 170 kg, the monomer supply was stopped, the entire amount of the polymer slurry in the reactor was introduced into a deactivation tank, and deactivation treatment was performed with butyl alcohol. The solid polymer is recovered by centrifuging the slurry and dried with a dryer to obtain a powdery white powder 875.
I got kg. The intrinsic viscosity [η] _T of the obtained ethylene-propylene block copolymer was 2.18 dl / g and the ethylene content was 4.5% by weight. The polymerization ratio of the P part and the EP part was 84/16 as a weight ratio calculated from the weight of the ethylene-propylene block copolymer finally obtained and the amount of the polymer in the P part. Therefore, the ethylene content in the polymer in the EP part was 28% by weight, and the intrinsic viscosity [η] _EP was 6.4 dl / g.

The propylene-ethylene block copolymer obtained was kneaded and granulated under the same conditions as in Example 1. However,
As the polypropylene component, 70% by weight of the ethylene-propylene block copolymer, intrinsic viscosity [η] =
30% by weight of homopolypropylene with 1.35 and Q = 6.3
The EP content was made to be the same as in Example 1 using the mixture of The Q value of the P part is high, the weld appearance is poor, and the elongation at break is low.

Comparative Example 2 An ethylene-propylene block copolymer was polymerized in the same manner as in Example 1. However, the hydrogen concentration was increased during the polymerization of the EP part to obtain an ethylene-propylene block copolymer having an intrinsic viscosity [η] _EP = 2.8 of the EP part. With respect to this copolymer, pellets of a polypropylene composition were obtained in the same manner as in Example 1, a test piece was prepared by injection molding, and the physical properties and appearance of this composition were evaluated. [Η] _EP is low and impact strength is low.

Example 2 The hydrogen concentration in the reactor was adjusted so that [η] _p and [η] _EP were _adjusted to predetermined values, and the propylene / ethylene feed ratio was adjusted so that the ethylene content in EP was adjusted to a predetermined amount. The same procedure as in Example 1 was repeated except that Thus [η] _p =
1.11, Q value of crystalline polypropylene part = 3.6, 2
1.2% by weight of xylene-soluble part at 0 ° C., [η] _EP = 4.
2, EP part 12% by weight, EP part ethylene content 37%
To obtain a propylene-ethylene block copolymer. The same stabilizer and nucleating agent as in Example 1 were added to this propylene-ethylene block copolymer, melt-kneaded and pelletized in the same manner as in Example 1, and then a test piece was prepared by injection molding to obtain physical properties. Was measured.

Comparative Example 3 [η] _p , [η] _EP hydrogen concentration in the reactor to a predetermined value, and ethylene content in the EP to a predetermined amount, the propylene / ethylene feed ratio. Example [Embodiment 1] except that was changed to [η] _p = 1.13,
Q value of crystalline polypropylene part = 3.5, xylene soluble part at 20 ° C. is 1.2% by weight, [η] _EP = 2.5, EP part 1
A propylene-ethylene block copolymer having 2% by weight and an EP part having an ethylene content of 41% was obtained. This propylene
The same stabilizer and nucleating agent as in Example 1 were added to the ethylene block copolymer, and the mixture was melt-kneaded in the same manner as in Example 1 to obtain MF.
After making pellets of R = 31, a test piece was prepared by injection molding to measure the physical properties.

Example 3 A polymerization reaction was carried out in the same manner as in Example 1. However, [η] _p ,
[Η] The hydrogen concentration in the reactor is controlled so as to bring the _EP to a predetermined value, and the propylene / ethylene feed ratio is controlled so that the ethylene content in the EP comes to a predetermined amount.
The supply amount of the propylene / ethylene mixed gas was controlled to adjust the P content to a predetermined amount. Thus, [η] _p
= 0.83, Q value = 3.5, CXS = 1.1% by weight,
A [propylene] -ethylene block copolymer having an [η] _{EP of} 4.2, an EP portion of 16% by weight and an ethylene content of the EP portion of 42% by weight was obtained. This copolymerization resistance 87 parts by weight, average particle size 2.
A polypropylene / talc composite was obtained by melt-kneading 17 parts by weight of 5 μ of talc and the additive added in Example 1. As shown in Table 1, the flowability, rigidity and impact strength were excellent.

Comparative Example 4 A polymerization reaction was carried out in the same manner as in Comparative Example 1. However, [η] _p ,
[Η] The hydrogen concentration in the reactor is controlled so as to bring the _EP to a predetermined value, and the propylene / ethylene feed ratio is controlled so that the ethylene content in the EP comes to a predetermined amount.
The supply amount of the propylene / ethylene mixed gas was controlled to adjust the P content to a predetermined amount. The obtained propylene-ethylene block copolymer ([η] _p = 1.60,
Q value = 5.6, CXS = 2.7% by weight, [η] _EP = 5.
0, EP part 19% by weight, EP part ethylene content 28
%) In the same manner as in Example 3 except that 17 parts by weight of talc having an average particle size of 2.5 μm and an additive are added, and a small amount of SANPEROX TY-13 is added to improve fluidity, and melt kneading is performed. A polypropylene / talc composite material having MFR = 70 was obtained. As shown in Table 1, the rigidity was inferior to that of Example 3. Also, the flow mark is noticeable on the molded product,
The appearance was poor.

Example 4 Polymerization was carried out in the same manner as in Example 1. However, water in the reactor
Elementary concentration, propylene / ethylene feed ratio, propylene
/ [Ethylene] _p= 1.
75, Q value of crystalline polypropylene part = 3.6, CXS
Content 1.2% by weight, [η]_EP= 4.1, EP part 16 weight
%, Ethylene content of EP part 41% propylene-ethi
A len block copolymer was obtained. This propylene-ethyl
The same stabilizer as in Example 1 was added to the block copolymer.
Melted and kneaded into pellets, and then injection molded.
A test piece was obtained.

Comparative Example 5 Polymerization was carried out in the same manner as in Example 1. However, by changing the hydrogen concentration, the propylene / ethylene feed ratio, and the supply amount of the propylene / ethylene mixed gas in the reactor, [η] _p = 1.7.
8. Q value of crystalline polypropylene part = 3.6, CXS content 1.1% by weight, [η] _EP = 3.0, ethylene content 40% in EP part, propylene-ethylene block with EP content 16% by weight A copolymer was obtained. This propylene-ethylene block copolymer was added with the same stabilizer as in Example 4, pelletized by melt-kneading, and then a test piece was obtained by injection molding.

[0043]

[Table 1]

[0044]

Industrial Applicability The ethylene-propylene block copolymer and composition according to the present invention makes it possible to obtain a molded article which is excellent in low-temperature impact strength, rigidity and fluidity and has a good appearance.

Claims (1)

[Claims] 1. A propylene homopolymer or a crystalline polypropylene portion obtained by copolymerizing propylene with ethylene or an α-olefin having 4 or more carbon atoms in an amount of 1 mol% or less and the composition of ethylene and propylene are in a weight ratio of ethylene / propylene = 20. / 80 to 60/40 ethylene-propylene random copolymer part, and (1) the intrinsic viscosity [η] _{P of the} crystalline polypropylene part is 0.8 to 2.0 dl / g, the molecular weight measured by GPC. Ratio Q value (weight average molecular weight M _w / number average molecular weight _MN ) of 3.
0 to 5.0, the content of xylene solubles at 20 ° C. is 1.5 wt% or less, (2) the intrinsic viscosity [η] _{EP of the} ethylene-propylene random copolymer portion is 3.5 to 8.5, and (3) An ethylene-propylene block copolymer in which the ethylene-propylene random copolymer portion accounts for 5 to 20% by weight of the total polymer.